Urbanisation brought an increasing prevalence of groups of high-rise buildings and raised new questions about their impact on local wind flow conditions and the wind energy harvesting potential. The focus of this study is two-fold. First, it gives insight into the interference effects around high-rise buildings based on the level of building exposure to the wind and the position of surrounding buildings. Second, it addresses wind energy resources above the roof in terms of the Wind Power Density (WPD), turbulence intensities and skew angle. Three study cases are defined from two configurations: The isolated high-rise building and the group configuration of five identical buildings in two different arrangements. Two wind directions are included, 0°and 45°. Validated large-eddy simulations are used due to their superior simulation capabilities. The strongest separation around the building is noted in the group configuration when the two upstream buildings produce the “channelling effect” and with other surrounding buildings compress the flow around the central one. Regarding wind energy harvesting, maximal value of 2.5 is recorded at 45°wind angle in the “cross” shape arrangement. Considering the different wind turbine types, vertical-axis wind turbines seem the most promising option for wind energy harvesting above the roof.